To maintain an ecological balance within an aquarium, it is necessary to keep the water in the aquarium clean. Cleaning is often accomplished by pumping water from the aquarium to a filter device, filtering the water through a filter medium, and returning the filtered water to the aquarium. Such filtering devices generally include an internal pump driven by an electric motor for pumping the water through the filter medium. During operation of the pump and motor assembly, it is sometimes desired to control the flow provided by the pump. Devices exist in the prior art for this purpose. However, some are difficult to operate and/or are not provided integrally with the remainder of the filter device.
In general improvements in filtering devices are sought.